Missile velocity indicating system



Sept. 13, 1960 J. D. TEAR ET AL 2,952,846

MISSILE VELOCITY INDICATING SYSTEM Filed April 17, 1957 7 Sheets-Sheet 1kz z (/P 2 AXIS X AXIS IN ME N TORS JAMES D. 7' EAR J0$PH M 0 '0/V0F/P/0HE/V/PY E MC/IEN/VEY ROBERT D. 69035 FREDERICK J." MC/IEOWN ATTORNEY m-1960 J. D. TEAR ETAL 2,952,846

MISSILE VELOCITY INDICATING SYSTEM Filed April 17, 1957 '7 Sheets-Sheet2 PL AN5 2 l/v VE/V TORS 1 5 0552% OSEPH a QZQ? FEEDER/CK Mcms-awxvATTORNEY.

Sept. 13, 1960 J. D. TEAR ET AL 2,952,846

MISSILE VELOCITY INDICATING SYSTEM Filed April 17, 1957 7 Sheets-Sheet 5FREDER/C/(J EO adv-W" A 7 Twelve y Sept. 13, .1960 J. D. FEAR EFALMISSILE VELOCITY INDICATING SYSTEM Filed April 17, 1957 7 Sheets- Sheet5 llllllllIlIlll.lllllnllllllllllllllI-llllllllllll] 8 a m) m x Am w j2? a m 3% A m M m 3% A v i 4 M d f F R .T- L A m w m m m m r m mmw 2 V MA- X If X V l IE7 L m W m mm m a a W MW: I 2' M m b n M a w 4 n 1N 3 M A5 A A Ry A 2 v v I. M m n 2 o a .fc. ,7, m w p .K g f R M 5 m m 4 m L L2 L 2 5A 3 VAL 0 AL 1 AL 21 BC 4 f 1/. s 0/ I, 0/ 02 4 F C y 5 5 fR 1 mo a a e 1 A m A l H w z J 0. h A M R wr Q; R z R a R 2 5 "2 Z E; F R REvDE s urn s fl m Z1 M m i m i M 1 "LU L1- X I'LL \r a r P P w u n 1 m Mw V M 4 M a M MM 8 m H mww A 3 a A w m A A n 2 c m I. v N L? a 2 9 7 a mn 2 m U H U 3 Aec 3 V W 9 I (Q 11v VEA/TORS 1% 7271/? Roz-35R? FREDERICKTI'ORNE Y MISSILE VELOCITY INDICA'IING SYSTEM.

Filed Apr. 17, 1957, Ser. No. 653,499

10 Claims. (11. 343-7 This invention relates to ai'rcratt telemeteringsystems and more particularly to a system for measuring the velocity ofan airborne missile from a ground station location.

Many conventional systems for obtaining the velocity of an airbornemissile from measurements at a single ground station relay ondiflerentiating techniques performed upon available radar data forsuccessive positions of the missile in flight. The velocity determiningaccuracy oi such systems is known to be poor since differentiatingsystems provide the velocity of'the missile by dividing a smalldisplacement of the airborne missile by the small time interval for suchdisplacement. Obviously small errors in the numerator and/ ordenominator can result in larger errors in the quotient. As a means ofincreasing the accuracy of conventional distance measuring systems, datais often obtained from a plurality of ground stations positioned along apreselected missile flight path in short and long base line systems.Neither the single station nor base line systems can yieldinstantaneously the missile velocities because of the need. to determinea change in distance over a finite interval of time. Even such systemswhich incorporate automatic computers require approximately two to tenseconds for the complex diiferentiating computations. Delays of thisorder seriously limit the desirable range safety function. In longbaseline systems, it is not uncommon to have the computation time extendinto weeks for the desired solutions.

A principal object of this invention is to provide a new system forautomatically and continuously indicating the three rectangular velocitycomponents of an airborne missile from a single ground station having ashort base line configuration of antennas.

Another object of the invention is to provide a new system forindicating the velocity of an airborne missile from a ground stationlocation, wherein the velocity data is provided and displayed for themissile substantially at the instant of its occurrence.

Another object of the invention is to provide a new system for moreaccurately measuring the velocity of an airborne missile from a groundstation location.

Still another object of this invention is to provide a new system forindicating the velocity of an airborne missile from a ground stationhaving a short base line configuration of antennas and an improvedautomatic computer component.

' In general the invention resides in the utilization of Doppler eifectmeasurements which are directly proportional to the missile velocitycomponents. As contemplated, a high frequency oscillator with itsassociated antenna, control circuits and power supply is installed on anairborne missile, the oscillator having a high degree of frequencystability. At a ground station location, there are provided fourantennas 1A, 2A, 1B and 2B in a short base line configuration to receivethe continuous wave transmission from the oscillator in the airbornemissile. Antennas 1A and 2A are positioned along a north-south base linewhile the 1B and 2B antennas are ate-r" t positioned along an,intersecting east-west base line, the four antennas being equally spacedfrom the point of intersection of the base lines. Generally, thefrequency of the transmission from the oscillator on the airbornemissile as received by the two pairs of baseline antennas is dilferentfor each antenna, the frequency being determined by the Doppler efiectas a consequence of the different radial velocities of the missilerelative to each of the antennav locations; In the proposed circuitry,base line equipment connected to. each base line pair of antennasincludes receivers to demo'dulate' the Doppler frequencies andassociated circuitry to measure the D01) pler frequencies. The signalsfrom the base line equipment represent the Doppler components which aredirectly proportional to radial velocity components V and V and to thedifference of the. radial velocity components (V1AV2A) and (V1B-V2B),wherein. VIA, V252, V 1 and V are the radial velocities of the airbornemissile relative to the four antenna positions. Instrumentation radarator near the origin of the intersecting base lines provides therangedistance r, the elevation angle qt and the azimuth angle 0- of themissile. Additionally, the radar-directs and slaves the four antennasthrough electromechanical servo systems for improving the reception atthe antenna. In the event that the radar antenna is displaced from thebase line origin, a parallax computer is provided to compensate for theofi-origin distances and angles. The seven continuously availablequantities V V13, (VIAT'V2A), (V1BV2B), r", and 6 are channeled to twocomputers, viz., a digital computer to obtain ballistic data and ananalog computer for range safety data.

In the disclosure of the invention a new and relatively simple analogcomputer is instrumentated to automatically yield the missile velocitycomponents V (longitude), V (latitude) and V (altitude) in accordancewith the following formulas which will be derived hereinafter:

2 cos S sin 61+ V cos S sin- 0 i 2L=distancebetween antennas on samebase line.

In this disclosure two embodiments of the base line equipment will bedescribed. Base line equipment A for the north-south antennas isidentical with the base line equipment B for the east-west antennas andin one embodiment each base line equipment comprises two receiversconnected to their associated antennas, two electronic counters to yielddigital outputs and two converters to yield analog outputs. Thetransmission from the airborne missile as received by the two antennasin each base line system is mixed, filtered and amplified in the baseline receivers and then channeled to two counter networks, one networkyielding the digital velocity and direction of V by counting the numberof Doppler cycles in a finite interval of time and the othernetworkyielding the digital time quantity T and its algebraic sign. Thequantities T for the first base line equipment O on the base line.

and T1343 for the second base line equipment represent the difference inthe Doppler frequencies of the transmission received by the two antennasin each base line system by measuring the time intervals for a finitenumber of Doppler difference cycles. These quantities are related to thedesired quantities (V V and (.V -V in accordance with the parameters ofa specific system. In the proposed circuitry, velocity directions for V'V (V A-V and (V V are determined by the introduction of bias frequenciesfrom local oscillators. For data processing in the range safety analogcomputer, the digital output from the counting networks is converted 'toanalog quantities by converter circuitry.

In another embodiment of the base line equipment, dynamic measurementsare made on a standing wave system connected to the two antennas alongeach base line; As contemplated, one end section of a variable microwavephase shifter, which is connected to one antenna through a wave guide,converts the linearly polar- .ized waves into circularly polarizedwaves. The rotatable section, of the phase shifter reverses thedirection of the circularly polarized waves of the first section anddelays the signal in accordance with its angular position, The other endsection of the phase shifter restores the wave to linear polarization.The angular position .of the rotary phase shifter is controlled by afollow-up servo mechanism system and a probe inserted into a wave guidesection connected between the third section of the phase shifter and thesecond baseline antenna will provide the null sensing element for theservo system. Adiflerentiating circuit energized by a responsepotentiometer in the servo system will yield the difference of theradial velocities of the missile relative to each antenna in the pair ofantennas. The radial velocity of the missile relative to one antenna ismeasured in similar microwave circuitry by substituting a stable highfrequency oscillator for one antenna in each pair of antennas, thefrequency of the oscillator being equal to the frequency of theoscillator in the airborne missile.

. The features of the invention will be understood more clearly from thefollowing detailed description taken in conjunction with theaccompanying drawings in which:

Fig. 1 is a three dimensional diagram of the geometry of an airbornemissile relative to two pairs of antennas at a ground station location;

Fig. 2 is a two dimensional diagram of the geometry Fig. l in plane Apassing through the A-base line and the position of the airbornemissile;

Fig. 3 is a two dimensional diagram of the geometry of Fig. 1 in a planeB passing through the B-ba'se line and the position of the airbornemissile; Fig. 4 is a block diagram of the new missile velocity measuringsystem; Fig. 5 is a block diagram of one embodiment of th base lineequipment in Fig. 4; t

Fig. 6 is a schematic and block diagram of another embodiment of thebase line equipment in Fig. 4; and Fig. 6a is an explanatory diagramshowing the block symbols-used in Fig. 6.

Figs. 7a, 7b, 7c, 7d and 7e are block diagrams of the analog computer inFig. 4.

Referring to the three dimensional diagram in Fig. 1,

antenna being located at a distance L from an origin Another pair ofreceiving antennas 1B and 2B are disposed in the ground plane and alongan east-west base line through the origin 0, each antenna being locatedat a distance L from the origin 0. .For convenience the base lines areestablished in a three dimensional rectangular coordinate system havingan X axis referenced in the east direction, a Y axis referenced in thenorth direction and a Z axis referenced in the zenith direction. Anairborne missile at point P which is displaced at a range distance Rfrom the Origin 0 ha 4 an instantaneous velocity represented by thevector V. In this short base line configuration, the range distance R isappreciably greater than the separation distance 2L between the antennasin either base line. Point P lies on sphere 10 having its center at theorigin 0 and the missile velocity vectonV relative to this sphere 10 hasa radial component V and a tangential component V The rectangularcoordinates of point P are x, y and z and its polar vector along thedistance R has an angle'a with the X axis, an angle 18 with the Y axisand an angle 2 with the Z axis. The point P at range R can also belocated by an azimuth angle 0 measured from the Y axis and an elevationangle measured from the ground plane. r

The geometry of Figs. 1 in plane A and plane B" which pass through thepoint P and the Y axis and X axis respectively are shown in Figs. 2 and3.

From the geometrical relationships in Fig. 1,-

'x= R cos sin 0=R cos p 1 K1 1) y=R cos cos 0=R cos )3 -ir e- 'e WDilferentiating Equations 1, 2 and 3 v V,' =fRo c sin oc+V icos CL V=-R, sin e-l-V cos' e V R isinz l V cosi I a 7 wherein R A and R are theranges of point P from point positions 1A and 2A respectively.

From the equality, cos E: l--sin E cos E I cost? 5 4mm R L 2RL cos Leos. I I v RL cos 6 also, y I i I 4 (Ya'-. 1A)= A 7A z irl-VA 1 i COS sat-

(7 IE )=V COS "Y COS sin and from Equations 4 and 5 YA Sin an 7 1A- 2A)=A COS 'YA( 1A E2A-) A "5131 V IIA cos a+.B 311+ V cos 2} (1.7) 'YA( 1A+EZA) y I but VA 00$ 8 VB now from the relationship in Equati0n13 V S. :VV

A m 7A TA V V sin qb 1 (A cos sinB-l-Bcos -cos'0) (V1A 2A) R( 1A zA) Smsin Em-I-Sln 11 18 9 For a short base line configuration in which R ismuch R+Lcos B R-L cost? '1 V -V -V 2A) R, aIR +U+-2RLCOS VR +L 2RL cos V8111 B= also from Fig. 2

,greater than L, the'distances R R R and R are W/RZ-I-LLFZRL'COS B R +L.2-RL cos s Now, from the relationships in Equation 2 and Similarly,using Fig. 3

( in -m) VB cos 'y B(cos E -cos E V sin 'y B(sin Ein-l s'in E V (V1B 23)R( 1B 00S 2B) sin E -l sin E V --R;; approximately equal and for such acondition, therefore, 0 ,V V V VY=IB+VREOOS B t ,V CW wherein, 4 I R+Lcos B -R-L cos B V V V 2A) R VR +L +2RLCOS B R +L 2RL cost? In Fig. 41's shown a block diagram of amissile velocity 30 system whichimplements the new theory of operation as derived hereinbeifore. Astable high frequency osci'llator 20'having a transmitting antenna 21 isdisposed on an airborne missile '22. Four receiving antennas 1A, 2A, 1Band 2B are positioned at a ground station in accordance with thegeometry of Fig. 1, .antenna 1A and "2A being disposed along base line Aand antennas 11 13 and 2B.being disposed alongbase line B. Antennas 1Aand 2A are connected to A-hase line equipment by calbles 321 and 32,respectively. The A base line equipment has a digital and an :analogoutput which 'yields signals directly proportional to 'the radialvelocity. V of the missile 22 relative to the .antenna 'IA and thedifference in radial velocities (V V of the missile 22 relative to thetwo antennas in "thewbase line A. B hase line equipment '40 is identicalto A-base line equipment Now from the relationships in Equation 1 R 1B213)|: cos 5 sin 6; and

V =A+V cos sin 0 (16) To solve for V cos a+cos s+ cos 2:1 or

30, the B-base line equipment being connected 'to an- :tennas 11B and 2Bby cables 41 and 42 'so as yield the radial velocity V 13 of the missile22 relative to antenna 1B and the idiiference in radial velocities ('V V"of the missile 22 relative to the two antennas jin' ba'se "line B. As apractical expedient, the velocities V and V can be measured by countingthe number of Doppler frequency cycles in'a fixed "time interval and thevelocity diiferences (V 'V and (V :V 'can'be measure?! by time intervals'T and T1343 required for a finite number of Doppler differencefrequency cycles. The digital outputs of V sign of V and T from A-baseline equipment '30 and the 'digital outputs of V =W)[d cos a sin (n+5cos B sin ,8]

sign V and T 1 from .B-base line equipment 40 are channeled to a digitalcomputer 50 .by cables 33, 34, 3 5,

to an analog computer 51 by cables 52, 53, and 54, 55,

respectively, connected therebetween.

were An instrumentation radar system 60 having an antenna 61 located atthe ground station position to track the missile 22in flight. The radarsystem continuously yields the range R in cables 62 and 62, the azimuthangle in cables 63 and 63' and the elevation angle 4: in cables 64 and64. The radar sytem 60 also slavm and points the four antennas 1A, 2A,1B and 2B at the missile 22 by servomechanism systems (not shown) formaximizing the reception from the oscillator 20. In the event that theantenna 61 of the radar system 60 cannot :be located at the base lineorigin 0, a parallax computer 70 is provided to correct for theelf-distances and offangles corresponding to the off position of theradar antenna 61 from the origin 0, the parallax computer beingconnected at its input side to the cables 62, 63 and 64 from the radarsystem 60. The parallax computer 70 receives the off-distance positionof the radar an- -tenna 61 from the origin 0 through shaft 71 for the xordinate displacement, through shaft 72 for the y ordinate displacementand through shaft 73 for the z ordinate displacement, the output of theparallax computer 70 yielding the true range R, true azimuth angle 0 andtrue elevation angle s of the missile 22 as referenced from ,of thedigital computer 50, the digital computer having .its own parallaxcomputer incorporated therein with provision to receive theofif-distance corrections of the radar antenna 61 from theorigin 0through shafts 56, 57 and 58. The output side of the digital computer 50is connected to a Ballistic Data Recording and Indicating device 80 bycables 81, 82, 83 land 84, the digital computer yielding the velocity Vof missile 22 and its three coordinate components V V and V 'The analogcomputer -1 is connected on its othe input side to the cables 74, 75 and76 so as to receive the connected to a mixer 112 by a cable 113 througha filter-amplifier 114. A second-bias oscillator 115 having a frequency(f -H 1 is connected in beating relationship to the mixer 112 by a cable116, wherein f is a second bias frequency to establish the plus or minussign of the quantityif The output of the mixer 112 having theinformational quantity (fBZifdIA) is connected to the input side of afrequency cycle counter network 117 by a cable 118 through afilter-amplifier 119. The counter network 117 measures the radialvelocity V of the missile 22 relative to the antenna 1A by counting thenumber of input Doppler cycles in a finite time interval. The digitaloutput V and sign of V; A of. network 117 is connected to the cables 33and 34 of digital computer 50 and to a digital-to-analog converter '120by a cable 121. The analog output V of converter 120 is connected to thecable 52 of the analog computer 51.

The output side of the filter-amplifier 114 is additionally connected inbeating relationship to a' mixer 122 by a cable 123. A local oscillator124 having a frequency (fi -f is connected in beating relationship tothe mixer 105 by a cable 125. The output of the mixer 105 having theinformational quantity (f f true R, 0 and o quantities from theinstrumentation radar system 60. The output side of the analog computerFig. 5 is one embodiment in block diagram of the A-base line equipment30, the B-base line equipment being similar to the hereinafter disclosedA-base line equipment. The antennas 1A and 2A receive electromagneticenergy of frequency (f jzf and (fcif wherein f is the frequency of theoscillator 20 in the air- ..borne missile 22, f is the Doppler frequencyreceived by antenna 1A, and f is the Doppler frequency received byantenna 2A, the plus or minus sign being governed by whether the missileis flying towards the antenna or Way from the antenna, respectively. Itennas 1A and 2A are connected through the cables 31 and 32 to mixers100 and 101, respectively. A local .oscillator 102 having a frequency (f-h is connected in beating relationship to the mixers 100 and 101 by acable 103, the frequency i being a convenient lower intermediatefrequency. The output sides of mixers 100 and 101 having theinformational quantities (f if g) and (fmif zg) :are connected to mixers104 and 105 by cables 106 and 107 through filter-amplifiers 108 and 109,respectively. A bias oscillator 110 having a frequency of (f f f isconnected in beating relationship to the mixer 104 by a cable 111,

(Hawaiian) is connected to the input side of the mixer-122 by a cable126 through a filter-amplifier 127. Automatic gain control circuits 128and 129 are connected between the filter-amplifiers 127 and 109 andbetween the filteramplifiers 114' and 108, respectively,-for stabilizingthe circuitry of the base line equipment. The output of the mixer 122having the informational intelligence J i(f f is connected to afrequency period counter network 130 by a cable 131 through afilteramplifier 132. The counter 130 measures the difference in radicalvelocities (V V of the missile relative to the antennas 1A and 2A bymeasuring the time period T for counting a preselected number of Dopplerdifference frequency cycles, received by the antennas 1A and 2A as aconsequence of the radial movement of the missile 22 relative thereto.The digital output T of the network 130 is connected to the cable 35 ofthe digital computer and to a digital-to-analog computer 133 by a cable134. The analog output (V -V of converter 133 is connected to the cable53 of analog computer 51.

As an example of practical circuit values and parameters for theembodiment disclosed in Figs. 1, 2, 3, 4

wherein f is a first bias frequency to establish the plus orminus signof the quantity (f -f and P "is a convenient lower frequency than f Theoutput ,side ofthe mixer 104 having the informational quantity and 5,the selected frequency f of the airborne oscillator 20 may be 12,000megacycles per second when it is desired to measure the velocity of themissile 22 having a velocity in the range'of zero to 15,000 feet persecond.

The Doppler frequency f relative to any of the antennas,

1A, 2A, 1B or 2B would then vary 12 cycles per second for each foot persecond of missile radial velocity V in accordance with the formula,

Rfo fa wherein C=speed of light in feet per second (approx. 1 X 10 Sincethe missile can be in-coming or out-going rela-- tive to any antenna,the direction of travel must be known. As the received frequencydecreases when the missile is out-going and increases when the missileis incoming, the direction of travel may be determined from the Dopplermeasurement. By allowing the Doppler frequency shift of kilocycles tovary about a second bias frequency i of 320 kilocycles, the frequency tobe counted by the counter network 117 will always be positive and lessthan 1 megacycle, thereby simplifying the counter mechanism. 7

The Doppler frequency shift (f -f is employed to measure the differencein Doppler velocities (V -V of the missile 22 relative to the antennas1A and 2A. For the selected parameters, the Doppler difference frequencyis 12 cycles per second for each foot per second of difference invelocity when the base length L is 100 yards, the difference in radialvelocity varying between 0.001 and 30 feet per second. Since themeasurement of difference in radial velocity is actually in terms ofangular velocity, the clockwise or counterclockwise movement of themissile relative to the origin must be determined. This can. bedetermined by em.- ploying a first bias frequency f of 2740 cycles persec- The Values of (fdlA 'fd2A)' and (fern-fem) will then normally varybetween 2380 and 3100 cycles per second for the selected parameters ofthe system.

' From the formula =n/t wherein t represents the time required tocount ncycles, it appears that two methods are available for determining thefrequency 1. Either i may be preselected and 11 measured, or n maybepredetermined and I measured. When highest accuracy is desired, it isadvisable to use frequency cycle counting at high frequencies andfrequency period counting at low frequencies. For the preselectedparameters of the disclosed system, the counting network 117 counts thenumber of Doppler cycles received by antenna 1A in 0.0416 seconds andthe counting network measures the Doppler dilference time interval (T inseconds for counting. 100 cycles of the Doppler shift frequency. For thechosen parameters:

Another embodiment of the A-Base line equipment 30 of Fig. 4 is shown inFig. 6. In the disclosed standing wave measuring system, antenna 1Awhich received the frequency (f if is connected by a wave guide 199 toone end section 201 of a variable microwave phase shifter 200 having acenter section 202 and another end section 203, the phase shifter beingcapable of advancing or retarding a standing microwave by any angle in acontinuous manner through any number of cycles. The phase shifter 200consists of three sections 'of round wave guide, each section containinga plate of dielectric material (not shown). The middle round wave guide202 is free to rotate while the end sections 201 and 203 are fixed. Thefirst section 201 converts the linearly polarized wave from antenna 1Ainto a clockvw'sepolarized wave. The center section converts theclockwise polarized wave into a counterclockwise circularly polarizedwave and delays the signal in accordance with its angular position. Thethird section 203 restores the wave to linear polarization and isconnected through a wave guide 204 to the antenna 2A which received thefrequency (f if A probe 205 inserted in the wave guide 204 provides anull sensing element for a follow-up servo system comprising anelectrical adding network 206, a servo-amplifier 207 and a servomotor208, one input of the adding network 206 being connected to the probe205 by a conductor 209. The output side of the adding network 206 isconnected to the servomotor 208 through a servoamplifier 207 by cable210. The output shaft 211 of servomotor 208 drives the shaft of therotary phase shifter 200 and the shaft of a potentiometer 212, thepotentiometer 212 being connected across a DC. reference voltage 213.Slider 214 of potentiometer 212 is connected to the other input ofadding network 206 by a conductor 215 and to the input of adifferentiator 216 by a conductor 217. During the flight of missile 22,the servomotor 208 will constantly adjust the rotary phase shifter so asto maintain a null point at probe 205. The movement of servomotor shaft211 varies the output of the potentiometer 212. As the output of thispotentiometer is connected to the input of the dilferentiator 216, theoutput of the latter device will contain the analog quantity ('V -Vwhich is placed in the analog computer 51 by the connection 53. If it isdesirable to operate the digital computer 50 for Ballistic Datarecording, an analog-to-digital converter 218 is connected to the outputof dilferentiator 216 by a cable 219. The output of the converter 218has the digital information T fortthe digital computer 50. In order toobtain the analog and digital output for the radial velocity ,Vm, a waveguide 299, a rotary phase shifter 300, a wave guide 304-, a probe 305,an adding network 306, a servoamplifier 307, a servomotor 308, apotentiometer 312 and a ditferentiator 316 are interconnected identiecally as are components 199, 200, 204, 205, 206, 207, 208, 212 and 216,respectively; Wave guide 299 is connected to antenna 1A and wave guide304 is connected to anoscillator 320 having a frequency f equal to thefrequency of the oscillator 20 in the airborne missile 22:. The outputof the dilferentiator 316 will contain the analog quantity V for theanalog computer 51. If it is desirable to also operate digital computer50 for Ballistic Data recording, an analog-to-digital converter 318 isconnected to the output of diiferentiator 316 by a cable 319. The outputof the converter 318 has the digital information V and sign of V whichare introduced to the computer 50 by cable connections 33 and 34,respectively.

Figs. 7a, 7b, 7c, 7d and 7e are block diagram representations of theanalog computer 51 in Fig. 4, the computer receiving the input analogquantities R, 0, V (V1AV2A), V13 and (V1BV2B) in thfi Cables 74, 75, 76,52, 53, 54 and 55, respectively, and yielding the desired intelligence VV and V in accordance with the following formula which are abovederived:

(A cos s sin 6+B cos qb cos 6) wherein Referring to Fig. 7a, the cables75 and 76 having the information quantities of azimuth angle 6 andelevation angle of the missile 22 are connected to acoarse-fineservomechanism system 501 and 502, respectively. The outputshaft 503 of servo-mechanism system 502 is operatively connected todrive one input shaft of adders 504 and 505 while the output shaft 506of servomechanisnr system 501 is operatively connected to drive theother input shaft of adders 504 and 505. Adder 504 subtracts thedisplacements of its two input shafts 503 and 506 to yield adisplacement of its output shaft 507 equal to (q5-0). Adder- 505 addsthe displacements of its two input shafts 503 and 506 to yield adisplacement of its output shaft 508 equal to (+0). Shafts 507 and 508are operatively connected to drive the shafts of resolvers 509 and 510,respectively. One electrical output of resolver 509 having theinformation sin (45-0) is connected to an adding servomechanism system.510 by a cable 511 and the other output of ia ebasae resolver 509 havingthe information cos (-'-0) is connected to an adding servomechanism 512by a cable 513. One electrical output of the resolver 510 having theinformation sin (+0) is connected to adding servo- 12. w is connected atits input side to the shaft 76 (4b) and to the cable 512 V to yield thecomputation quantity (+V sin to'its output cable 570 The cable 570 isconnected to the other input of the adder 568 and adder mechanism system510 by a cable 514 and the other 568 yield the computation quantity V toits output cable electrical output of resolver 510 having theinformation 571. t cos (+0) is connected to the adding servomechanisrnAs shown in Fig. 7e, cable 548 having the computation 512 by a cable515. When the servomechanism sysquantityoV cable 554 having thecomputationV and terns reach equilibrium, shaft 516 of addingservomechacable'571 having the computation quantity V are connism 510will displace in proportion to the computation nected to, the input sideof a function network 580, the quantity (cos sin 0) and shaft 517 ofadding servofunction network yielding a solution in accordance withmechanism 512 will displace in proportion to the comthe equation V=V +V+V A cable 581 connected putation quantity (cos 5 cos 0). to the outputside of function network 580 has the in- In Fig. 7b, an adder 520 isconnected at its input formation quantity V, V. being the resultantvelocity of side to the cables 52, 53, 54 and 55 having informationalmissile 22 relative to the base line origin 0. quantities V (V V V and(V V re- It is to be understood that various modifications. ofspectively, the adder 520 yielding the computation quanthe inventionother than those above described may be tity V in cable 521. effected bypersons skilled in the art without departing In Fig. 70, a multiplier525 is connected at its infrom the principle and scope of the inventionas defined put side to the cable 521 (V and to the shaft 516 intheappended claims. (cos sin 6 )v for yielding (V cos gb sin 0) to cableWhat is claimed is: 526. A multiplier 530 is connected at its input sideto 1. A missile velocity measuring system comprising a the cable 521 (Vand shaft 517 (cos cos. 9) to transmitting antenna and an oscillatoradapted to be disyield (V cos cos 0) to cable 531. The cable 74 posed onan airborne missile, said transmitting antenna having the rangeinformation R is connected to a servo.- 25 being connected in drivenrelation, to said oscillator, a mechanical system 540. The outputshaft541 of servo first and second pair of antennas at a ground station540 displaces in direct proportion to the range R and location, a baseline equipment device connected to each is operatively connected to anddrives the shafts of pair of antennas for measuring the radial velocityof adders 542 and 543. The other shafts-of adders 542 said oscillatorrelative to one antenna in each pair of and 543 are connected to shafts516 (cos sin 0) and antennas and for measuring the difference in theradial 517 (cos cos 0), respectively. The output shaft 544 velocities ofsaid oscillator relative to the two antennas of adder 542 having theinformational quantity of each pair of antennas, radar means having aradar antenna at the said ground station location for providing R cos 0sin 0) the range, elevation angle and azimuth angle of said 2L 2 poscillator, and computing means connected to the base line equipmentdevices-and to said radar means for yieldis connected to the cable 55 (VV The output illg the Velocity of Said Oscillatofof multiplier 545 incable 546 has the computation quan- {nissile Velocity measuring SystemComprising a m A) A dd 547 connected at i input id 40 transmitt ngantenna and an oscillator adapted to be disto the cable 526 (V cos sin0) and to the c l posed on an airborne missile, said transmittingantenna 54 yields the computation i y V i a being connected in drivenrelationship to saidoscillator, a cable 548. The output shaft 550 ofadder 543 having first and second p of antennas at a ground t t l h i fti l quantity cation, each of said pairs of antennas being disposedalong one of two mutually perpendicular base lines having an R COS 4,COS 0 intersection point (Leach antenna being spaced at a disf 2 tance Lfrom the said point 0, a base line equipment de- 7 vice connected toeach pair of antennas for measuring is connected to drive the shaft of amultiplier 551. The the'rafhal velocity of Said oscillator relative oneh other input side of multiplier 551 is connected to the 5 tehha 1h eachPa1r P hh and meahnhg the h Cable 53 (V1A V2A)- T e output of l i li 551ference in the radial velocities of said oscillator relative in thecable 552 has the computation quantity (B) to the two antennas of eachpa r of antennas, radar means An adder 553 connected at its input sideto the cable havmg a f' Phtehha at the slde'grohhh Stahoh loca- 531 coscos 0) and to the cable 552 tron for providing the range (R) elevationangle (g5) yields the computation quantity V in a cable 554. 5ahdazlmhth angle (a) of saldpsclllatgr, and computmg As shown in Fig.7d, a multiplier 560 is connected h to the h ase hhe eqhlpment means hat its input side to the cable 516 (cos sin 6) and th to said radarmeans for yielding the rectangular velocity cable 548 (-A) to yield theinformational quantity i and z P the h osfhllatol' 111 (A cos qb sin 0)in its output cable 561. A multiplier cordahce Wlth the mathemahcalrelahohshlp: 562 is connected at its input side to the cables 554 (-B) 0and to the cable 517 (cos cos 0) to yield the informa- VX=A+VR cos Smtional quantity (B cos cos' B) in its outputcable'563. VY=B+VR cos it 90 and An adder 564 is connected at its input side to the cable 1 51-6(-A cos sin 0) and to the cable 563 (B cos R sin 1 (A sin cos cos 0) cos0) for yielding the informational'quantity (A cos 5 S n 45 sin 0+B cos 3cos 0) in its output cable 565. At its wherein: input side, a functionmultiplier 566 is connected to the R 1 cable 565 (A cos sin 0 +3 'cos 1:cos 9) and to the A=(V V cos qssin 0] shaft 76 to yield the computationquantity 1 i BV V (A cos (1: sin lH-B cos cos 0)]' I 2Z cos cos in itsoutput cable 567. The cable 567 isconnected to =WM one input of an adder568. A function-multiplier 569 4 and V is the radial velocity of saidoscillator relative to one antenna in one pair of antennas;

V is the radial velocity of said oscillator'relative to the otherantenna in said one pair of antennas;

V is the radial velocity of saidoscillator relative to one antenna inthe other pair of antennas;

V is the radial velocity of said oscillator relative to the otherantenna in said other pair of antennas.

3. A missile velocity measuring system as claimed in claim 1 whereinsaid each base line equipment device includes a first mixer connected toone antenna of one pair of antennas, a second mixer connected to theother antenna of said one pair of antennas, a first local oscillatorconnected in beating relationship to the said first mixer, a third mixerconnected to the output side of the said first mixer, a second biasoscillator connected in beating relationship to the said third mixer, afirst counter means connected to the output side of said third mixer formeasuring the radial velocity of said oscillator relative to said oneantenna of said one pair of antennas, said first mixer being alsoconnected in beating relationship to the said second mixer, a secondcounter means connected to the output side of said second mixer formeasuring the difference in the radial velocities of said oscillatorrelative to each antenna in said one pair of antennas.

4. A missile velocity system as claimed in claim 3 wherein said firstand second counter means are adapted to yield digital and analogueoutputs and said computing means includes a digital computer connectedto the digital output of said first and said second counter means andanalog computer connected to the analog output of said first and saidsecond counter means.

5. A missile velocity measuring system as claimed in claim 4 whereineach base line equipment means includes a fourth mixer, a firstamplifier connected in driven relationship to said fourth mixer, saidfourth mixer and said first amplifier being in the said connectionbetween said first mixer and its associated antenna, a second amplifierin the said connection between said first and said third mixers, a thirdamplifier in the said connection be tween said third mixer and saidfirst counting means, a fifth mixer, a fourth amplifier connected indriven rela tionship to said fifth mixer, a sixth mixer connected to theoutput side of said fourth amplifier, a first local oscillator connectedin beating relationship to said sixth mixer, a fifth amplifier connectedin driven relationship to the said sixth mixer, the said fourthamplifier, the said sixth mixer and the said fifth amplifier being inthe said connection between the said second mixer and its associatedantenna, a sixth amplifier in said connection between said second mixerand the said second counting means, and a second local oscillatorconnected in beating relationship to the said fourth and said fifthmixers.

6. A missile velocity measuring system as claimed in claim 5 wherein thesaid connection between the said radar means the said computing meansincludes a parallax correcting means for correcting the range, azimuthangle and elevation angle as measured at the location of said radarantenna to the true range, azimuth angle and elevation angle of the saidoscillator relative to the said point 0.

7. A missile velocity measuring system as claimed in claim 6 whereinsaid analog computer comprises a first adder connected to the analogoutput of said first and said second counting means of the pair of baseline equip ment devices for yielding the computation quantity Vresolving means connected to said parallax correction means forobtaining a first resolved computation quantity cos sin 6 and a secondresolved computation quantity cos 5 cos 0, a first means connected tosaid resolving means, the said parallax correcting means and each ofsaid counting means of said pair of equipment devices for obtaining thesaid computation quantity A and the said computation quantity B, a firstmultiplier connected at its input side of said first= adder and saidresolving means for obtaining the computation quantity V cos :1: sin 0,asecond adder connected at its input side to said first multiplier andsaid first. means for obtaining the computation quantity V a secondmultiplier connected at its input side to said first adder and saidresolving means for obtaining the computation quantity V' cos p cos 0, athird adder connected at its input side to said first means and saidsecond multiplier for obtaining the computation quantity V a secondmeans connected to said first means, said resolving means and saidparallax correcting means for obtaining the computation quantity a thirdmeans connected to said first adder and said parallax correcting meansfor obtaining the computation quantity V sin 4:, and a fourth adderconnected at its input side to said second means and said third meansfor obtaining the computation quantity V 8. A missile velocity measuringsystem as claimed in claim 1 wherein each base line equipment deviceincludes a rotary phase shifter, a first wave guide connected betweenone antenna of one pair of antennas and said rotary phase shifter, asecond wave guide connected between the other antenna of said one pairof antennas and the other side of said first rotary phase shifter, aprobe disposed in said second wave guide, nulling means connected incontrolling relationship to said phase shifter and in controlledrelationship to said probe for maintaining a null at said probe, avariable voltage source connected in controlled relationship to saidphase shifter and a differentiator connected across said variablevoltage source.

9. A missile velocity measuring system as claimed in claim 8 whereineach base line equipment device includes a second rotary phase shifter,a third wave guide connected between said one antenna of said one pairof antennas and said rotary phase shifiter, a second oscillator having afrequency equal to the first mentioned oscillator, a fourth wave guideconnected bet-ween said second oscillator and said second rotary phaseshifter, a second probe disposed in said fourth wave guide, a secondnulling means connected in controlling relationship to said second phaseshifter and in controlled relationship to said second probe formaintaining a null at said second probe, a second variable voltagesource connected in controlled relationship to said second phase shifterand a second differentiator connected across said second variablevoltage source.

10. A missile velocity measuring system as claimed in claim 1 whereineach base line equipment means comprises a first rotary phase shifter, afirst wave guide connected between one antenna of said one pair ofantennas and said first rotary phase shifter, a second wave guideconnected between the other antenna of said pair of antennas and theother side of said first rotary phase shifter, a first probe disposed insaid second wave guide, a first adding network, one input side of saidfirst adding network being connected to said first probe, a firstservomotor connected in driven relationship to said first addingnetwork, a DC. voltage source, a first potentiometer connected acrosssaid DC. voltage source, said first servomotor being operativelyconnected to said first rotary phase shifter and to said firstpotentiometer for driving a first difierentiator, said firstpotentiometer being connected in driving relationship to said otherinput side of said first adding network and to said firstdifferentiator, a second phase shifter, a third wave guide connectedbetween said one antenna of said one pair of antennas and said secondphase shifter, a second oscillator having a frequency equal to the firstmentioned oscillator, a fourth wave guide connected between said secondoscillator and said second phase shifter, a second probe disposed insaid fourth wave guide, a second adding network, one input side of saidv 15 16 second adding network being connected to saidsecond tiometer,and a second differentiator, said second potentiprobe, a secondservomotor connected in-drivenfrelationometer being connected in drivingrelationship to said ship to said second adding network, a second'potentiother input side of said second adding network and to. ometerconnected across said DC. voltage source, said said seconddifferentiator. second servomotor being operatively. connected to drive5 said second rotary phase shifter and said second potenr- No referencescited.

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